The invention relates to a disposable injector having at least one cylinder-piston unit, the piston of which can move between two stroke end positions in relation to the cylinder, the cylinder-piston unit comprising at least one sealing system that seals a compensating space from the surroundings.
Such a disposable injector is known. During the transfer-pumping, germs from the air could get into the cylinder interior.
U.S. Pat. No. 4,030,498 A discloses a syringe which has two seals spaced apart on a piston rod.
WO 2008/037 329 A1 discloses a cylinder-piston unit with a cylinder and a piston which is guided therein and which is sealed off in a sterile manner by a rubber seal, wherein the cylinder and the piston enclose a chamber that can be filled at least temporarily with active substance, and the cylinder has at least one discharge element at its front end. When the piston is actuated, two individual static sealing elements are transferred from their respective sealing position into a parked position located in the parking area, wherein each sealing element in the parked position touches only the cylinder wall or only the piston wall.
The present invention is therefore based on the problem of developing a disposable injector in which the aforementioned disadvantage cannot occur.